1. Field of the Invention
The present invention relates to a pressure-contact terminal formed with pressure-contact blades between which an end of an electric wire is press-fitted.
2. Description of the Related Art
Conventionally, there is a known pressure-contact terminal 1 as a pressure-contact terminal of this type as disclosed in U.S. Pat. No. 4,940,425 as shown in FIG. 1. As shown in FIG. 1, the pressure-contact terminal 1 is formed at its front end side with a contact portion 2 for connection to an opposed terminal and at its the other side with an electric wire connecting portion 3 for retaining an electric wire and for connection to the electric wire. The electric wire connecting portion 3 is formed with pressure-contact portions 6, 7, 8, and 9 hammered inward to bulge from a pair of side walls 4 and 5. The electric wire connecting portion 3 is formed at its rear end portion with a pair of electric wire retaining chips 10 and 11.
By the pressure-contact terminal 1 with such a structure, by press-fitting a covered electric wire in the electric wire connecting portion 3, the pressure-contact portions 6, 7, 8, and 9 cut the cover to bring an exposed core into contact with the pressure-contact portions 6, 7, 8, and 9, thereby establishing connection.
In the above-described pressure-contact terminal 1, the pressure-contact portions 6, 7, 8, and 9 to be connected to the electric wire and to retain the electric wire have shapes formed by hammering the side plates 4 and 5 inward and bending tip end portions (tip end portions in bulging directions). Therefore, axial retaining force of the pressure-contact portions 6, 7, 8, and 9 is small if load is applied in an axial direction to the electric wire connected to the pressure-contact terminal 1.
Therefore, it is an object of the present invention to provide a pressure-contact terminal that can reliably retain an electric wire against attraction in an axial direction of the electric wire.
The present invention has been achieved with such points in mind.
According to a first aspect of the present invention, there is provided a pressure-contact terminal comprising: a contact portion to be in contact with an opposed terminal and formed on a tip end side of the pressure-contact terminal; and an electric wire connecting portion formed on a rear end side of the pressure-contact terminal, the electric wire connecting portion having a bottom plate and a pair of side plates formed by bending from both sides of the bottom plate in the same direction, the pair of side plates being formed with a plurality of pairs of pressure-contact portions; wherein at least a pair of pressure-contact portions out of the plurality of pairs of the pressure-contact portions has a pair of pressure-contact blades; and each of the pair of pressure-contact blades includes: a pressure-contact blade main body cut and bent up from the side plates; a blade portion formed on an outer periphery of the pressure-contact blade main body to cut a cover portion of a covered electric wire; a contact portion continuously formed from the blade portion to be in contact with a core of the covered electric wire; and a core retaining portion for retaining the core, the core retaining portion being formed on a lower portion side of the contact portion so as to project in such a direction as to approach to the other one of the pair of pressure-contact blades and to be brought into contact with the cover portion of the covered electric wire, thereby preventing coming off of the covered electric wire from the pressure-contact portions.
In this pressure-contact terminal, the covered electric wire is placed on the electric wire connecting portion and is pressed-fitted between the pressure-contact blades by using a pressure-contact jig or the like. If the covered electric wire is press-fitted between the pressure-contact blades, the cover portion of the covered electric wire is cut by the blade portions and the exposed core comes in contact with the contact portions. As a result, the covered electric wire is electrically connected to the pressure-contact terminal. In this case, end faces of the cut cover portion come in contact with the pressure-contact blade main bodies and with the core retaining portions formed on the pair of pressure-contact blades of at one of the plurality of pairs of pressure-contact portions. Thus, the covered electric wire can be reliably retained against attraction in an axial direction of the electric wire.
According a second aspect of the invention as it depends from the first aspect, in addition to an arrangement of the first aspect, there is provided a pressure-contact terminal, wherein the core retaining portions have retaining contact portions to come in contact with the core to be connected in a conductive manner to the core.
In this pressure-contact terminal, in addition to the operation of the first aspect, because the core of the covered electric wire comes in contact with the retaining contact portions, the electric connection between the covered electric wire and the pressure-contact terminal can be established.
According to a third aspect of the invention as it depends from the first or the second aspect, in addition to arrangements of the first and second aspects, there is provided a pressure-contact terminal, wherein the other pair of pressure-contact portions which have not the pressure-contact blades are formed in such a manner that the pair of side plates are projected inward each other by hammering operations.
In this pressure-contact terminal, in addition to the operation of the first and second aspects, the electric wire can be reliably retained by using the pressure-contact portions formed by hammering. In other words, although the pressure-contact portions formed by hammering the opposite side plates to project inward have small retaining force against the attraction in the axial direction of the covered electric wire, the electric wire can be retained reliably against the attraction in the axial direction of the electric wire because the core retaining portion is formed on the pressure-contact blade of at least one pressure-contact portion.